i got our kayden a 'chilly bone' from our pet store.
it's cloth...and you just wet it, and then place it in the bag (included), then place it in the freezer for about an hour.
it keeps her busy for quite a while.
and you can just toss it in the washing machine when it gets dirty

good luck.
i haven't found anything that keeps her from chewing on my fingers and toes when she's 'in that mood'